The occurrence and control of Phomopsis species causing Phomopsis symptoms and dieback in Western Cape Vineyards


Project Number
P04000084

Project Title
The occurrence and control of Phomopsis species causing Phomopsis symptoms and dieback in Western Cape vineyards

Project Leader
Halleen, F

Institution
Stellenbosch University. Department of Conservation, Ecology and Entomology

Team Members
Halleen, F
Du Plessis, I
Moyo, P

Project Description
The has been increase in symptoms of Phomopsis in Western Cape vineyards. This phenomenon has been observed in table and wine grapes. Recent research revealed the presence of 12 Phomopsis species in grapevines of South Africa. Pathogenic studies on green shoots indicated a variation in virulence. Some of these Phomopsis spp. are increasingly being associated with trunk disease symptoms. A survey of these pathogens in cordons of grapevines in South Africa was conducted in 2011.

A detailed survey vineyards in the Western Cape with typical Phomopsis symptoms and bleached canes should be completed to to determine whether Phomopsis viticola is the only causative agent, or if P. amygdali or other Phomopsis spp. contribute to this disease. If the latter is found to be the case, it might explain the lack of disease control observed in recent years. Climate change (longer, wet spring) and the significant increase and diversity in other fruit crops in close proximity to vineyards could also act as inoculum sources in the Western Cape with typical symptoms and bleached canes should be performed to determine whether Phomopsis viticola is the only causative agent, or if P. amygdali or other Phomopsis spp. contributes to this disease. Climate change and the significant increase and diversity in other fruit crops in close proximity to vineyards could also act as inoculum sources and contribute to this phenomenon. Suitable field trials will be formulated to evaluate the efficacy of fungicides. The role and infection pathways of these Phomopsis spp. in the grapevine trunk and the relation to the cane and leaf blight symptoms will also be investigated.

Objectives Determine which species contribute to this disease by conducting detailed surveys of vineyards in the Western Cape Conduct surveys of other fruit and woody hosts surrounding vineyards to determine their status as alternative hosts. Confirm findings by means of pathogenicity studies. Evaluate and implement effective control measures.

Poster(s)
Lesuthu, P, Moyo, P, Mostert, L, Spies, C F J and Halleen, F. 2017. Diaporthe nebulae sp. nov. and other Diaporthe species associated with Phomopsis dieback in South African grapevines. 4-7 July, Reims, France.

Spies, C F J, Moyo, P, Bester, M C, Lesuthu, P, Du Plessis, I L, Van Jaarsveld, W J, Mostert, L and Halleen, F. 2017. Hiding in the bushes: Woody plants near vineyards harbour grapevine trunk pathogens. Poster presented at the 10th International Workshop on Grapevine Trunk Diseases, 4-7 July, Reims, France.

Lesuthu, P, Mostert, L, Spies, C F J and Halleen, F. 2017. Diaporthe sp. nov. and first report of D. cynaroidis, D. nov. and D. serafiniae on grapevines in South Africa. Poster presented at the 50th SASPP Congress. 15-19 January, Drakensberg, South Africa.

Presentation(s)
Spies, C F J, Moyo, P, Bester, M C, Lesuthu, P, Du Plessis, I L, Van Jaarsveld, W J, Mostert, L and Halleen, F. Woody plants near vineyards harbour grapevine trunk pathogens. Paper presented at the 50th SASPP Congress. 15-19 January, Drakensberg, South Africa.

Spies, C F J, Moyo, P Bester, M C, Lesuthu, P, Du Plessis, I L, Van Jaarsveld, W J, Mostert, L and Halleen, F. 2017. Diversity and host range of trunk disease pathogens in South Africa. Paper presented at the INRA UMR SAVE. 20 July, Bordeaux, France.

– Record end –

Generic selectors
Exact matches only
Search in title
Search in content